Improvement in pressure-gauge for hydrostatic presses



'lutrd N bittet l @sind @Wina relief-valve.

' 'THOMAsHARBOTTLn orA BROOKLYN, NEW YORK.y Lnmlant No. 89,992, dazed May 11. 1869.

IMPROVEMENT PRESSURE-GAG-E `FOR HYDROSTATIC PRESSED.

The Schedule referred to in these `Lettrs Patent and `making part of the same.

` To all whom' it concern: i

l specification.

In the drawings- 'Figure l represents a sectional view, as the only clear method of showing the arrangement and the working of the gauge. y

Figure 2 is an elevation, showing the stirrup and `fthe pump or press, or any suitable apparatus, the pis- `ton A rises as the pressureincrealses, contracting the spring B until the `stud-pin D engages With the stirrup i D, instantly raising thecheck-valve E.

The pressure being constant ou check-valve E, it

closes as soon as the pressure is relieved, thereby acting as a safety-valve, as well as a pressure-indicator.

' In those devices where the pressure-piston is made to serve also the purpose of an escape-valve, as heretofore used, the resistance is so lgreat that the current `of steam or water passing its edge will rapidly out it away, and its action will in a short time vary materially from the desired' indication by the register; and` A until the desired pressure is attained, when it is raised by the stud C, lifting it by means of the slotted stirrup D, and as there is a fractional amount of pressure on the top of the valve E, as compared with that on the under side of the piston A, together with the downward current of the escape through the valve, both' tending to close it, the moment the piston A is relieved of the surplus pressure, the valve E promptly closes. What I yclaim as my invention, and desire to secure by Letters Patent, is-

The pressure-indicating piston A, combined withrent of the escape have a tendency to close said valve, l

as andfor the purpose set forth.

Witnesses: THOS. HARBOTTLE.

f GHAs. E. FROST,

` A. G. J oNEs; 

